What is the deal with this?

As a relatively new fan of the series I'd feel a lot more comfortable playing/helping the team if I could get my hands on the vehicles in a custom setting. I'd also like an opportunity to explore the maps on my own and be able to mess around with some of
the game mechanics/physics with a friend or two outside of a competitive arena. Is this not possible?

Also, am I missing something or is there no way to quit out of a lobby once the game ends? It seems like they make you stay there all the way up until the next game is ready to go and then, and only then, are you given the option to quit. Who in their
right might thought this was a good idea? You're obviously going to have people who want/need to quit after a match and to make them wait for the next game to launch is not only infuriating but it also seems to shoot its own matchmaking in the foot because
what are full teams after letting nobody leave after the previous game, aren't going to be full when people start dropping out. If someone can explain to me what I'm doing wrong by not being able to exit or at least try to explain to me the madness behind
what appears to be an epic design flaw, I'd appreciate it.

Thanks for the response Panda, and wow, this might be a deal-breaker for me which is such a shame because I do enjoy the gameplay. But it becomes intensely frustrating when it appears that the matchmaking process and so many important details associated
with it, as well as something as simple as custom games, appear to be all-out ignored. Also, no way to alter kits except for in-game??? It almost, -scratch that. I
does feel disrespectful.

When server browsing you can click your right stick for browsing options. You can then set to unranked matches. Not the same as private match but at least you can experiment without killing your stats. Check your server location while there. Mine was set
to Europe and I live in Cali. Made a huge difference in connecting and game play.

Maybe they'll release an onslaught mode for BF3, that would be cool. But as far as learning to play BF, it's always been 'trial by fire', meaning it's you against other people. Good luck and enjoy yourself.